The present application relates to digital signal processing, and more specifically to systems and method for processing digital data to facilitate avoiding or reducing artifacts that may be introduced when the digital data is compressed, encoded, or otherwise subsequently processed.
Systems for facilitating avoiding, removing, or otherwise detecting artifacts in digitally encoded data are employed in various demanding applications, including video processing, encoding, and quality assessment, audio compression, and so on. Such applications often demand efficient mechanisms for compressing digital data without introducing human perceptible artifacts, such as excessive image banding in video frames.
Efficient mechanisms for avoiding or reducing problematic artifacts introduced in compressed digital data are particularly important in video processing applications, where compression algorithms, such as those employing quantization, often introduces perceptible artifacts, such as excessive banding, which may substantially degrade video appearance.
Generally, video data quantization involves compressing a range of values of transformed image data into discrete quantization levels, where the step size of quantization is specified by the Quantization Parameter (QP) applied to a given block of image pixels occurring in a frame of video.
Compressing information in the video frames through quantization can result in the color banding (also called false contour) artifact, which can be particularly noticeable in areas of a video frame used to represent a color gradient. The width of the resulting color bands may be a function of the QPs used to compress video frames by an encoder.